Radio access networks (RANs) provide for radio communication links to be arranged within the system between a plurality of user terminals. Such user terminals may be mobile and may be known as ‘mobile stations’ or ‘subscriber units.’ At least one other terminal, e.g. used in conjunction with subscriber units, may be a fixed terminal, e.g. a control terminal, base station, eNodeB, repeater, and/or access point. Such a RAN typically includes a system infrastructure which generally includes a network of various fixed terminals, which are in direct radio communication with the subscriber units. Each of the fixed terminals operating in the RAN may have one or more transceivers which may, for example, serve subscriber units in a given local region or area, known as a ‘cell’ or ‘site’, by radio frequency (RF) communication. The subscriber units that are in direct communication with a particular fixed terminal are said to be served by the fixed terminal. In one example, all radio communications to and from each subscriber unit within the RAN are made via respective serving fixed terminals. Sites of neighbouring fixed terminals may be offset from one another or may be non-overlapping or partially or fully overlapping.
RANs may operate according to an industry standard protocol such as, for example, the Project 25 (P25) standard defined by the Association of Public Safety Communications Officials International (APCO), or other radio protocols, such as the terrestrial trunked radio (TETRA) standard defined by the European Telecommunication Standards Institute (ETSI) or the Digital Mobile Radio (DMR) standard also defined by the ETSI. Communications in accordance with any one or more of these standards, or other standards, may take place over physical channels in accordance with one or more of a TDMA (time division multiple access), FDMA (frequency divisional multiple access), or CDMA (code division multiple access) protocol. Subscriber units in RANs such as those set forth above send user communicated speech and data, herein referred to collectively as ‘traffic information’, in accordance with the designated protocol.
Many so-called ‘public safety’ RANs provide for group-based radio communications amongst a plurality of subscriber units such that one member of a designated group can transmit once and have that transmission received by all other members of the group substantially simultaneously. Groups are conventionally assigned based on function. For example, all members of a particular local police force may be assigned to a same group so that all members of the particular local police force can stay in contact with one another, while avoiding the random transmissions of radio users outside of the local police force group.
When an event or incident occurs, such as a fire or accident, numerous different groups may respond to the incident, including for example, direct first responders such as police, fire, and medical groups and supporting responders such as utility, traffic control, crowd control groups, among others.
In some examples, a dispatcher at a dispatch console disposed in the RAN may control operation of the subscriber units arriving at the incident scene, and may instruct each subscriber unit or group of subscriber units to manually join one or more groups particularly associated with the incident so that all subscriber units responding to the incident can communicate with one another about the incident. For example, verbal or text messages may be broadcast from the dispatch console to all subscriber units in a police group, a fire group, and a medical group. In emergency situations, e.g. in case of an accident, however, it takes a significant amount of time for the dispatcher to manually create one or more talk groups, identify subscriber units and/or groups responding to the emergency situation, and to correspondingly assign the groups, as well as to monitor and assign subsequently arriving subscriber units to those groups. Such manual processes causes some delay as additional exchanges of information is required and causes some additional delay as a result of required manual operations of varying dispatch console operators, among other issues.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.